Identify the location of oxidation in an electrochemical cell. a. Oxidation occurs at the cathode. b. Oxidation occurs at the anode. c. Oxidation occurs at the salt bridge. d. Oxidation can occur at either the cathode or the anode depending on the overall redox reaction that is occurring.
The Correct Answer and Explanation is:
Correct Answer:
b. Oxidation occurs at the anode.
Explanation:
In an electrochemical cell, oxidation and reduction are the two half-reactions that drive the overall redox process. Oxidation is the process where a substance loses electrons, while reduction involves gaining electrons. These two processes occur at different parts of the electrochemical cell, each with specific functions.
Oxidation always occurs at the anode of the cell. During oxidation, electrons are removed from the species at the anode, and these electrons then flow through the external circuit to the cathode. At the cathode, reduction takes place as electrons are accepted by another species. This flow of electrons is what generates electrical energy in devices like galvanic cells or batteries.
The salt bridge, mentioned in option c, does not participate in oxidation or reduction directly. Its role is to maintain electrical neutrality by allowing ions to migrate between the two half-cells. Without the salt bridge, charge buildup would eventually stop the electron flow.
It is important to note that in both galvanic (voltaic) and electrolytic cells, oxidation always occurs at the anode. The key difference is that in a galvanic cell, the anode is negative because it supplies electrons to the external circuit, while in an electrolytic cell, the anode is positive because an external power source drives electrons away from it. Regardless of cell type, the location of oxidation remains fixed at the anode.
The idea that oxidation can occur at either electrode, mentioned in option d, is incorrect. The terms anode and cathode are defined based on where oxidation and reduction occur, not based on the specific reaction. Therefore, oxidation always happens at the anode, and reduction always happens at the cathode in any electrochemical setup.
